fflush(NULL) returns error

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@636 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 22 insertions, 13 deletions

diff --git a/nuttx/lib/lib_wrflush.c b/nuttx/lib/lib_wrflush.c
index cc2f65543..73e24afec 100644
--- a/nuttx/lib/lib_wrflush.c
+++ b/nuttx/lib/lib_wrflush.c
@@ -1,5 +1,5 @@
 /****************************************************************************
- * lib/lib_wrlush.c
+ * lib/lib_wrflush.c
  *
  *   Copyright (C) 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
@@ -90,22 +90,31 @@
  *
  ****************************************************************************/
 
-/****************************************************************************
- * Name: lib_wrflush
- ****************************************************************************/
-
 int lib_wrflush(FILE *stream)
 {
-#if CONFIG_STDIO_BUFFER_SIZE > 0
-  /* Verify that the stream is opened for writing... flush will return an
-   * error if it is called for a stream that is not opened for writing.
-   */
+  /* Verify that we were passed a valid (i.e., non-NULL) stream */
 
-  if (stream && (stream->fs_oflags & O_WROK) != 0)
+#if CONFIG_STDIO_BUFFER_SIZE > 0
+  if (stream)
     {
-      return fflush(stream);
+      /* Verify that the stream is opened for writing... lib_fflush will
+       * return an error if it is called for a stream that is not opened for
+       * writing.
+       */
+
+      if ((stream->fs_oflags & O_WROK) == 0 ||
+          lib_fflush(stream, TRUE) == 0)
+       {
+         /* Return success if there is no buffered write data -- i.e., that
+          * the stream is not opened for writing or, if it is, that all of
+          * the buffered write data was successfully flushed.
+          */
+
+         return OK;
+       }
     }
+  return ERROR;
+#else
+  return stream ? OK : ERROR;
 #endif
-  return OK;
 }
-